Consumer demand exists for vehicles with moonroofs built into a panoramic glass exterior, that is, a uniform appearance of glass from the windshield to the backlite. Designing vehicles with these features creates tensions among design considerations including styling, occupant headroom, safety, the torsional rigidity of the vehicle, complexity, and durability.
A large panoramic moonroof can decrease the torsional rigidity by displacing some of the frame of the vehicle that would have been located in the roof, and it can impinge on headroom because the drive motor of the moonroof may be located in the rear center of the vehicle, only leaving room for a short rear middle passenger.
On the other hand, a smaller moonroof requires adding additional glass panels between the moonroof and the windshield or backlite or both. Additional glass panels introduce more “split lines” that divide the glass panes and may mar the styling. They also add complexity to the design of the vehicle by adding more parts, such as mountings, as well as necessitating different parts for moonroof and non-moonroof versions of the same vehicle model. Finally, the panels decrease durability by increasing maintenance demands and providing additional paths for water leaks.
Accordingly, an opportunity exists to design a vehicle that provides attractive styling and spacious passenger headroom while maintaining safety and torsional rigidity, minimizing complexity, and enhancing durability.